Immunologic response to fungus is not universally associated with chronic rhinosinusitis

In the December 2009 issue of this journal, Orlandi et al presented a study in which peripheral blood mononuclear cells (PBMCs) from chronic rhinosinusitis (CRS) patients (5 from Texas, 5 from Utah) and seven nonhealthy controls were stimulated with fungal extracts. Despite the small numbers, they confirmed important aspects of previous studies: 1) CRS patients' PBMCs react to certain fungal stimuli by producing significantly (P < 0.05) higher amounts of interleukin (IL)-5 and IL-13 when compared to controls; 2) CRS patients have an enhanced humoral response (significantly elevated immunoglobulin [Ig] G levels to Alternaria); and 3) CRS patients react independently from an IgE-mediated allergy, as evidenced by that fact that nonallergic CRS patients also produced IL-5 in response to fungal stimuli. Unfortunately, the authors chose not to highlight their positive results. They emphasized what they failed to demonstrate, specifically an immune response to fungi above a certain threshold in some patients (Utah) with milder CRS. However, these results are potentially explained by the different methods used, and care should be applied when interpreting their results.